Roadway construction.



T. H. FLERB.

ROADWAY CONSTRUCTION. APPLICATION FILED JAB. 13, 1913.

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Patented Nov. 24, 191 i vi a 7. r

THOMAS HOCAR'I' FLERE, OF ,KEW, VICTORIA, AUSTRALIA.

ROADWAY CONSTRUCTION.

Specification of Letters Patent. 1

Patented Nov. 24, 1914.

Application filed January 13, 1913. Serial No. 741,777.

Australia, have invented certain new and useful Improvements in andRelating to Roadway Construction; and I do hereby declare the followingto be a full, clear, and

exact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

My invention is one, of that class which relates to roadway constructionintended to secure comparatively dustless and particularly durable andwaterproof surfaces. My roadway will be usefully resilient, resist motorand horse trafiic, withstand the cleaning operationsof sweeping andwatering,

and will give horses firm foothold. It will do away with side slippingof motor vehicles.

In carrying this invention into efiect I may use expanded metal or thelike as a reinforcement in combination with other features hereinaftermentioned.

The road surface is to be given any de-, sired gradient and camber, abed being provided of suitable material below the road surface to securea firm foundation, which may be of concrete rubble. On the foundation Iprovide a cushioning resilient waterproof layer, ordinarily a bituminouscompound, that is stone screenings, furnace slag :or suitable materialwith bitumen or the like, or it may consist of a rubber-likecomposition; this layer may however in some cases bepartly loose,coarsesand. On the saidlayer I set heated blocks of granite having topsurfaces measuring for example 3 inches square, though the invention isnot thereto limited." OrI use other knownmaterial which is not easily,for the external or eXposed-to-weather roadways, perishable like wood,or not easily ground into dust like basalt. I lay the blocks, which areordinarily deeper than, they are broad, in rows, each row forming one orseveral curves or arcs; straightjoints across the roadway are avolded,as well as continuous longitudinal parallel olnts. ThIS, arrangementreduces wear; the joints are yaried uat I will, by

changing the curve radius, and the length of the arcs to include adifferent angle.

The blocks have either trapezoidal, square, or like suitable tops, andare to be assembled in position by the aid ofa curved or appropriateimplement, at every second or third course, but there will neverthelessbe cracks left between the blocks, to be filled in as described later,to produce an arrangement which I compare to some extent with thearrangement of teeth in a head,-that is, the blocks are caused to haveindividual resilience to shock, though they might even touch at parts. Ifill the bases and middles of the cracks with dry heated powdered orgranular granite, slag, quartz, or such like suitable material. I tapthe blocks to make the powder settle, then I pour into the joints orcracks melted elastic waterproof nonfracturing material, for example,some artificial rubber-like compound which will re sist the streetconcussions and temperature changes to which the blocks are to besubjected;or melted bitumen is used. This resilient joint filling willthen be located at the top of each crack, and extenddown to about themiddle, but not to the base thereof.

I dress the top faces of the blocks with any suitable (as atarry)surfacing substance, free from ingredients soluble in water. Thisdressing, after a few days, in warm dry weather canberepeated withadvantage to fill any uneveniplaces which may have developed. By thetraffic and the cleansing of the road, part of the filling between theblocks will in time be removed, but I replace it periodically.

The above and further details of construction will be understood fromthe accompanying diagrammatic drawings.

Figure 1 represents a vertical section across part of a roadway; Fig. 2a plan View of part of the roadway; and Fig. 3 is like Fig.2 but showsmodifications, including a difference near the curb. Fig. 4 shows on alarger scale a joint and itsfilling.

In the drawings 1 represents the under part of the road foundation, 2its middle, and 3 its upper part; any suitable foundation which is firmand dry will do.

In Fig, 1 at the right hand side, a layer 3f,-which I usein somecases,'is shown of expanded metal, or coarse wire netting. l is thelayer over the foundation. This layer may consist of bitumen or materialas aforesaid which will give a cushioning effect; it is in some casesmixed with a small proportion of solid material as stone screenings orslag. 5 are granite or suitable blocks, which have upper surfacesadapted to be dressed as indicated to form the roadway. Between theseblocks there will be spaces 6 which I fill with in part powderedmaterial and in part a non-fracturing material of waterproof resilientcharacter, as referred to hereinafter. v

7 in Fig. 2 is a gutter course; and in Fig. 3 8 represents a curb; inFig. 3 the gutter course 9 consists of elongated blocks set obliquely tocurb 8. The invention is not directed to any arrangement of gutter orcurbing, the illustrations being examples only of forms which may beemployed.

Between the courses of blocks 5 are curved and transverse joints 10.Each curve will extend across all or only some portion of the road; aseries of curves is ordinarily adopted to make up the full width.

In Fig. 2 a complete curve is shown in each course, and portions ofother curves. The curve radius may be varied, and need not be the sameas regards those curves which have ends which meet. In Fig. 2 the curveshown has about the minimum of effective flatness and length, and inpractice the length is increased, but without reaching the length of aquadrant; or the various joints would, at the ends of the curves, run indirections which are not advantageous relatively to trafiic. Joints 10give superior results as compared with common transverse joints.

The blocks 5 are (except as indicated later) of uniform shape and size,or approximately so; this keeps the expense of laying and replacing to aminimum. Granite blocks do not break as flat as wood blocks are cut, butit is an advantage to have them somewhat rough, so this roughness ispurposely utilized. The roughness of the vertical walls of the cracksbetween the blocks enables the joint fillings to much better resist thepulling out of any block during traffic. Each roughness underneath ablock helps the latter to grip its cushion ing layer 4i; and each toproughness helps to prevent the slipping of motor cars or horses, givinga fine grip to both. The avoidance of slipping is additionally promotedby the described positioning of the blocks relatively to one another,and by the nature of the materials used as described. Where curves "ofthe block courses meet, special blocks are in some cases used, as inFig. 2, though meeting devices may be varied. As illustrated. blocks '13are peaked onone' side ,terruptions by blocks 13.

and recessed on the other side; they may be of any suitable size. Blocksas 12 are also used in some cases different in shape to blocks 5, byhaving the sides making the walls of joints 6 less. nearlyparallel.Between blocks 12 is a joint 11 not continuous longitudinally of theroad, on account of in- Joints 6 are not continuous longitudinally ofthe road from one course of blocks to the next. A filling of rubbercompound or bitumen is used in all cracks between the blocks extendingdownward from the traffic surface, as 6, 10 and 11, the powder 14:(inserted as previously explained) being covered with this filling l5,and each block can then move slightly under trafiic. During great heatit has been found that ordinary meltable fillings between j oints riseand spread upon the road, but in my case the melted material will sink alittle deeper into thelower part of the joints between grains of thepowder 1 1 not previously reached.

I may 'omit or modify some details described, providing matter isretained which I claim hereinafter.

Having described this invention what is claimed by Letters Patent is 1.In a road construction, the combination with a foundation, of a surfacecomprising arcuate units assembled into courses multi-arcuate in" ahorizontal plane, abutment units connecting adjacent arcs in alternatecourses, coiiperable units connecting adjacent arcs in the remainingcourses, said units having reversely-inclined meeting faces adapted toabut and form breaking joints with the abutment units of contiguouscourses.

2. In a roadway construction, the combination of a foundation consistingof a bed of concrete rubble, wire netting embedded insaid concreterubble, a layer of resilient waterproof material overlying said bed, anda surface comprising units assembled on said resilient Waterproofmaterial in courses arcuate in a horizontal plane.

3. In a roadway construction, the combination of a foundation consistingof a bed of concrete rubble, wire netting embedded in said concreterubble, a layer of resilient waterproof material overlying said bed, asurface comprising units assembled on said resilient waterproof materialin courses arcuate in a horizontal plane, a powdered filling insertedbetween adjacent units and a resilient waterproof material inserted overi said powdered vfilling.

4'. In a roadway construction, the combination of a foundationconsisting of a bed of concrete rubble, wire netting embedded in saidconcrete rubble, a layer of resilient yvaterproof materialoverlyingsaid-bed, -a.

surface" comprising units assembled "into courses mu1ti-arcuate in ahorizontal plane, waterproof naterial inserted over said 10; abutmentunits connecting adjacent arcs in powdered filling.

alternate courses, e06 erable units connecta In witness whereof I havehereunto set ingdadjacenlt1 arcs in t e reimainilng courses, my hand inthe presence of two witnesses. sai units aving reverse y-inc inecmeeting faces adapted to abut and form break- THOMAS HOOART FLERE' ingjoints with the abutment units of con- Witnesses:

tiguous courses, a powdered filling inserted GEORGE G. TURRI,

between adjacent units, and a resilient BEATRICE M. LOWE.

copies of this patent may be obtainedfor five cents each, by addressingthe Gommissioner of Estimate Washington, D. 0.

